(Reuters) -The U.S. Army awarded Lockheed Martin ( LMT ) a multi-year contract worth $4.5 billion for its air defense Patriot Missiles system, the Pentagon said on Friday.

The Patriot system is one of an array of sophisticated air defense units supplied by the West to help Ukraine, as it continues its defense against Russia's invasion.

The contract covers 870 PAC-3 MSE missiles and associated hardware.

Lockheed is manufacturing the newest version of the interceptors that arm the Patriot, known as PAC-3 MSE, which cost about $4 million each, according to Army budget documents.

(Reporting by Nathan Gomes in Bengaluru; Editing by Shinjini Ganguli)